Abstract

The term alien hand syndrome appeared in the literature over three decades ago, although the first description was probably recorded almost a century ago (Fisher 2000). The term was originally used to describe the patient’s inability to differentiate their own left hand from the examiner’s left hand when placed in their right hand, behind their back. However the term has evolved, and the terminology is confusing. Alien hand syndrome, alien limb syndrome and alien limb phenomenon are synonymous and can occur in either the arms or legs. The syndrome can be broadly divided into two types, an anterior syndrome and a posterior syndrome.

THE ANTERIOR ALIEN HAND SYNDROME

This is the classic syndrome. It is a motor disorder defined by involuntary hand or arm movements that occur either in addition to or instead of a planned or willed movement. The movements are complex and do not look like a recognizable